As more states, municipalities and agencies deploy electronic tolling solutions to help generate new funds and reduce congestion at tollbooths, there have been increased calls for standardization in the industry. While a handful of tolling solutions have dominated the market in the United States, most employ proprietary or otherwise non-interoperable technologies. This means that drivers who frequently pass through different states or cities may require multiple transponders to navigate each system.

The call for nationwide interoperability has risen to the level of the U.S. Congress. In fact, the federal government had called for electronic tolling interoperability by October 2016 as part of the Moving Ahead for Progress in the 21st Century Act (MAP-21). While that deadline has come and gone, industry groups such as the International Bridge, Tunnel and Turnpike Association (IBTTA) have been working diligently toward a final design for interoperability in the United States. These groups are working closely with the Federal Highway Administration, and have secured funding to conduct ongoing testing that will ultimately lead to a formal recommendation to the Congress. This is expected to happen in late 2017.

A relative newcomer in the tolling space is the ISO 18000-6C RFID air-interface protocol. ISO 18000-6C, often referred to as 6C, is an open-standard communications protocol based on the EPC Gen 2 standard for passive UHF RFID tags. (The latest version of ISO 18000-6C is officially known as ISO 18000-63.) It was originally developed for supply chain applications (inventory management, asset tracking and so forth), but has established itself as a reliable, robust and cost-effective technology for electronic toll collection applications.

Since the tolling market's initial adoption of 6C, the protocol has steadily spread across the United States and around the world. To date, agencies in Colorado, Georgia, Louisiana, Ohio, Utah and Washington have adopted 6C as their primary tolling protocol. Furthermore, the state of California has begun legislative action to transition its statewide protocol to 6C. Outside of the United States, 6C has been adopted as the primary tolling standard in Argentina, Colombia, the Dominican Republic, Ecuador, India, Malaysia, Panama, Paraguay, Peru, the Philippines, Taiwan, Turkey, Uruguay and Vietnam. The 6C specification is open and evolving, and not only provides a basis for a nationwide tolling standard, but also addresses the increasing need for security and privacy as a growing number of drivers participate in electronic toll collection.

A Living Standard
RFID tags and readers complying with 6C can be sourced from a variety of suppliers. This competitive commercial market brings costs down and promotes innovation—both of which are a benefit to customers. In addition, 6C is reliable and accurate even at very high speeds, making it ideal for vehicle-identification applications. In 2010, the E-470 toll road in Denver, Colorado, and the Utah Department of Transportation were leaders in the adoption of 6C technology for electronic toll collection. Since then, other U.S. agencies and departments, such as WSDOT and SRTA, have implemented 6C solutions with great results.

As a "living standard," 6C is continuously evolving to meet the market's needs. The ISO standards-development process maintains full backward compatibility with previous versions of the technology, while simultaneously allowing new innovations and features to be rolled out to customers.